Dotted border on one side for JPanel
Is there a way to add a dotted border on only one side to a component Java Swing
like JPanel
or JLabel
?
The question does not duplicate the other question because this question is about a line border for one side. But I need a dotted border.
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The question does not duplicate the other question because this question is about line border for one side
Yes, this is a duplicate, because the API shows you how to use MatteBorder
with Icon
one hand. So, all you have to do is create a Dotted Line Icon. See the example posted in my code below.
Or the second option, not listed in the wiring, is to use CompoundBorder
to create the desired effect:
Border empty = BorderFactory.createEmptyBorder(0, -1, -1, -1);
Border dashed = BorderFactory.createDashedBorder(null, 5, 5);
Border compound = new CompoundBorder(empty, dashed);
By setting the size EmptyBorder
to -1, you set the merged size to 0, so it DashedBorder
will only paint on one side.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class DashedBorder extends JPanel
{
public DashedBorder()
{
// Use an Icon in the MatteBorder
JLabel label1 = new JLabel("Label Using a Matte Border");
add(label1);
Icon icon = new DashedLineIcon(Color.BLACK, 5, 1, 5, 0);
Border matte = BorderFactory.createMatteBorder(1, 0, 0, 0, icon);
label1.setBorder( matte );
System.out.println(matte.getBorderInsets(label1));
add(Box.createHorizontalStrut(100));
// Create a CompoundBorder using the DashedBorder
JLabel label2 = new JLabel("Label Using a Dashed Border");
add(label2);
Border dashed = BorderFactory.createDashedBorder(null, 5, 5);
Border empty = BorderFactory.createEmptyBorder(1, -1, -1, -1);
Border compound = new CompoundBorder(empty, dashed);
label2.setBorder( compound );
System.out.println(compound.getBorderInsets(label2));
}
static public class DashedLineIcon implements Icon
{
private Color color;
private int dashWidth;
private int dashHeight;
private int emptyWidth;
private int emptyHeight;
public DashedLineIcon(Color color, int dashWidth, int dashHeight, int emptyWidth, int emptyHeight )
{
this.color = color;
this.dashWidth = dashWidth;
this.dashHeight = dashHeight;
this.emptyWidth = emptyWidth;
this.emptyHeight = emptyHeight;
}
public int getIconWidth()
{
return dashWidth + emptyWidth;
}
public int getIconHeight()
{
return dashHeight + emptyHeight;
}
public void paintIcon(Component c, Graphics g, int x, int y)
{
g.setColor(color);
g.fillRect(x, y, dashWidth, dashHeight);
}
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("Dashed Border");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new DashedBorder());
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
}
}
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And I ended up with this solution, although it's a little more complicated:
private void drawBorder(Graphics g){
int x = this.getWidth();
float dash[] = {1.0f};
Graphics2D g2;
BasicStroke stroke;
g2 = (Graphics2D)g;
stroke = new BasicStroke(1.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER, 1.0f, dash, 0.0f);
g2.setStroke(stroke);
g2.setColor((Color) new Color(120, 120, 120));
g2.draw(new Line2D.Double(0, 0, x, 0));
}
panel = new JPanel(){
@Override
public void paintComponent(Graphics g){
drawBorder(g);
}
};
Here I have drawn the top line using methods Graphics2D
and using a class BasicStroke
to create dashes, which are actually dots, because the density array dash
tells it that it has a space 1
between dashes by dashes of lengths.
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